Generally, automatically guided vehicles (AGV) are used in large warehouses, factories, and/or shipyards in order to move or transport loads along predetermined paths. Since the AGVs transport loads along a predetermined path, each AGV does not require an operator to control or drive the AGV. Instead, AGVs generally transport the loads along the predetermined paths based upon a series of commands or signals received from a system controller. One exemplary AGV method and apparatus is disclosed in U.S. Pat. No. 6,721,638, entitled “AGV POSITION AND HEADING CONTROLLER,” the entire disclosure being hereby incorporated herein by reference. Typically, the AGVs are powered by a battery on-board the AGV to travel along the predetermined paths, and are not electrically connected to a system power source during normal AGV operation.
The predetermined path can be a series of rails (e.g., tracks) that require the AGV to travel along a particular path. Alternatively, a series of position markers that are detected by the AGV can be used to control the travel path of the ATV. Yet another alternative is a master controller that monitors the location of the AGVs and communicates navigational instructions to such AGV.
In certain AGV applications the AGVs load must be positioned accurately at the predetermined path termination including but not limited to positioning large assemblies at robotic stations during automated manufacturing processes. Accordingly, it is desirable for many applications that the AGV be positioned at a positioning point in an accurate manner so as to derive the most utility from the device.